(1) Field of the Invention
The present invention relates to a device for changing a pitch between light beam axes to another desired pitch, and a maskless substrate exposure apparatus which includes the device for changing the pitch between the axes of the light beams outputted from multiple light sources arranged in a matrix serve as its light source.
(2) Description of the Related Art
In the related art, to form a pattern on a printed circuit board, a TFT substrate or color filter substrate of a liquid crystal display, or a substrate of a plasma display by exposure, a mask that serves as a master for the pattern is produced, and this master mask pattern is transferred onto the above-mentioned substrate by exposure with a mask exposure apparatus.
However, substrates are becoming increasingly larger in size in recent years. Moreover, the time taken to design and manufacture these substrates is becoming increasingly shorter. In view of this, so-called maskless exposure methods without using any masks have been put into practical use. Examples of these maskless exposure methods include a method of generating a two-dimensional pattern using a two-dimensional spatial modulator such as liquid crystal or DMD (Digital Mirror Device) and subjecting this two-dimensional pattern to exposure on the substrate with a projection lens, and a method of performing drawing and exposure on a substrate with laser light by using an EO modulator or AO modulator while performing scanning by using a large-output laser and a polygon mirror. Although the former method enables drawing of a relatively fine pattern, the method increases apparatus cost. On the other hand, although the latter method enables drawing of a rough pattern over a large area and allows relatively low-cost production due to the simple configuration, it is difficult to perform high-precision drawing over a large surface area. Further, a large-output laser is required to make the throughput time shorter, which leads to high apparatus cost and also high running cost.
In view of this, there is known a pattern exposure apparatus which realizes short throughput time, low cost, and reduced running cost by using multiple semiconductor lasers as the light source (Japanese Patent Application Laid-Open Publication No. 2005-316349).